Catheter stylets

ABSTRACT

The present invention relates to a new adjunct to the insertion of a urethral catheter. It is a catheter stiffener and former made of a plastic rod which has the properties of being a flexible, resilient member capable of properly stiffening a urethral catheter or the like while also being sufficiently compliant to pre-shaping into various and multiple curvatures to facilitate insertion into a body cavity.

United States Patent 1 1 1111 3,867,945 Long Feb. 25, 1975 CATHETERSTYLETS 011 1 12335384251} Inventor: Wendell M. g 528 NW. ,5 /1 o erty 38 Oklahoma City Okla Primary ExaminerDalton L. Truluck Attorney, Agent,or Firm-Laney, Dougherty, Hessin [22] Filed: May-l4, 1973 & Fish [21]Appl. No.: 359,984

[57] ABSTRACT The present invention relates to-a new adjunct to the gz ig g g insertion of a urethral catheter. it is a catheter stiff- [58]Fieid ener and former made of a plastic rod which has the properties ofbeing a flexible, resilient member capa- [5611 References Cited ble ofproperly stiffening a urethral catheter or the like while-alsobeing-sufficiently compliant to pre- UNITED STATES PATENTS v shapinginto various and multiple curvatures t0 facili 2,l Wappler R {ateinsertion into a bod cavit I 2,458,305 1/1949 Sanders 128/348 y2,463,149 3/1949 Caine... 128/351 8 Clalms, 6 Drawing Figures PATENTEDFEB25 5975 l I I. I. I. I. I ,i. I. I. I. I. ll

Ill. ill I. Isl I. h I Ill III III! ibi CATHETER STYLETS BACKGROUND OFTHE INVENTION use with the Foley urethral catheter.

2. Description of the Prior Art The prior art includes various types ofcatheter stylets, not only for use in Foley-type urethral catheters butother catheters as designed for insertion in particular body cavities,i.e. endotrachea catheters, trocar catheters, etc. Generally, the priorforms of stylets have been formed from wire or other rigid metallicmaterials. The prior art devices, especially as employed for insertionof urethral catheters, had inherent shortcomings due to the very fact oftheir necessary rigidity. The use of the conventional wire styletsrequired manipulation and insertion by a trained urologist inperformance of the routine as well as the more difficultcatheterizations, as the wire guide could very easily force the catheterto pierce the delicate wall of the urethra when not properly avoidingobstructions.

SUMMARY OF THE INVENTION The present invention contemplates a readilyexpendable catheter stiffener formed of desirably resilient material andit is particularly adapted for use with the Foley urethral catheter. Thestiffener and former consists of an elongated portion having theproximal end formed with a pre-selected curvature and a distal portionwith an enlarged diameter formed for co-action with the distal end ofthe Foley catheter. The proximal end of the stylet is formed with acurvature of optimum radius for encounter with the particularobstructions and curvatures present'along the urethral tract.

Therefore, it is an object of the present invention to provide acatheter stylet that is semi-rigid and sufficiently stiff to guide thecatheter during insertion and to prevent collapsing of the cathetertube.

It is still another object of the invention to provide a stiffener andformer which may be pre-formed into a variety of curves as selected toimplement insertion of the catheter device.

It is yet another object of the present invention to provide a catheterstylet having greater resiliency and which is unlikely to damage. thefragile lumen of the urethra when the catheter is inserted.

It is also an object of the present invention to provide a stiffener ofsimple design having no moving parts which is inexpensive to manufactureand may be disposable after a single usage.

It is therefore an object to provide a stiffener and former compatiblewith the design of the Foley urethral catheter which may be factoryinserted for sale with the Foley catheter as a unit, thereby reducingextra handling and contamination prior to its usage.

Finally, it is an object of the present invention to provide a stiffenerand former for use with the Foley catheter which will enable the moreroutine catheterization to be carried out by nurses or physiciansassistants without danger of damage to the urethral tract of thepatient.

Other objects and advantages of the invention will be evident from thefollowing detailed description when read in conjunction with theaccompanying drawing which illustrates the invention.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a top plan view of thestiffener and former as constructed in accordance with the presentinvention;

FIG. 2-is a side elevation of the: stiffener of FIG. 1;

FIG. 3 is a side elevation of an alternative form of stiffener;

FIG. 4 is a vertical section ofa Foley urethal catheter as is well-knownin the prior art;

FIG. 5 is a vertical section of the Foley catheter with stiffenerinserted; and

FIG. 6 is a section taken along lines 6-6 of FIG. 5.,

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to thedrawings in greater detail, FIGS. 1 and 2 show a catheter stiffener andformer 10 as constructed in accordance with the present invention. Thestiffener and former 10 is comprised of a rod 12 as securely joined oraffixed to what may be termed a handle 14. A proximal end portion 16 isthen preformed with a curvature 18 of selected radius, generally not toosevere but of sufficient curvature to allow optimum probing manipulationduring catheter insertion. A proximal tip 20 of rod 12 is rounded off toprevent damage to the proximal end portions of the catheter and/or theurethral wall.

Rod 12 is preferably formed from selected plastic materials having therequisite properties as to resil-' therein to ,be secured throughinterference fit. While the rod 12 and handle 14 are shown as beingformed in two separate pieces, it should be understood that thestiffener and former 10 can be formed unitarily in one piece throughconventional plastic molding practices.

While the stiffener and former 10 is shown in FIG. 2 as having acurvature 18, that which is known as the single curved or coude tip,some practitioners prefer, and the exigencies of certain therapeuticapplications may demand, a double curved tip 24 such as is shown in FIG.3. The curve 24 also subtends a relatively gentle curvature throughformation of two distinct angular bends 26 and 28.

FIG. 4 represents a standard form of Foley urethral catheter as is nowwell-known in the art. The Foley catheter is the particular subjectmatter of US. Pat. Nos. 2,428,407 and 3,l52,592 and the teachingsembodied therein have enjoyed wide application and success.Conventionally, insertion of the Foley catheter has required either theuse of a wire-form stylet with its attendant piercing and injuryproblems, or the attending physician has had to apply excessivelubrication and short stroke insertions of very time-consuming and un-Certain nature.

Briefly, the Foley catheter 30 consists of a distal portion 32 and tubeportion 34, the tube portion 34 being formed to include a drainage lumen36 and an inflation or control lumen 38. The Foley catheters may beformed as bi-Iuminal or tri-Iuminal tubes, at least one of which, suchas tube 38, is in communication with a balloon 40 which is sealinglyconnected about tube portion 30 proximate the proximal end 42 ofcatheter 30. Dash-lines 44 illustrate in section the balloon 40 after ithas been inflated to the attitude wherein it prevents withdrawal of tubeportion 34 from the bladder. The drainage conduit 36, of largerdiameter, is in communication with the fluid drainage holes 46 as formednear the proximal tip 42 of catheter 30. At the distal end, catheter 30is formed with a control tube 48 in communication with control lumen 38and serving to provide inflation and de-inflation control. A closureelement 50 within control tube 48 serves to maintain in- I flationpressure within the balloon 44 when in use. A

drainage outlet 52 in communication with drainage lumen 36 providesdrainage outlet for urine and collected fluids.

FIGS. 5 and 6 illustrate the catheter 30 with the stiffener and former10 inserted therein in operational position. Thus, the rod 12 isinserted along the entire length of drainage lumen 36 such that itsrounded tip end 20 is fully inserted up to proximal tip 42 of catheter30. The handle 14 of stiffener and former 10 is inserted within drainageoutlet 52 to provide a reasonably tight fit to maintain stiffener andformer l securely positioned within catheter 30 during entrymanipulation. The length of rod 12 has been established so as to extendthrough the length of the catheter shaft or drainage lumen 36 such thatthe handle 14 receives snug fit in the distal end thereof, i.e.,drainage outlet 52. In practice, the catheter is actually stretchedslightly to cause it to conform to the shape of the former and tothereby further decrease the diameter of the catheter 30 itself. Thisconstraint also serves to prevent buckling or collapsing of the catheterduring insertion and manipulation.

OPERATION In practice, the relatively resilient-stiffener and former 10is inserted into the catheter 30 as shown in FIGS. and 6-. Thereafter,the attending physician, attendant or nurse can then easily manipulatethe catheter 30 for probing entry into the urethra of the requiringpatient so that the proximal end 42 and drainage holes 46 are enteredsufficiently into the urinary bladder. Thereupon,.inflation control isexercised to inflate balloon 40 thereby to retain proximal end 42 withinthe bladder confines. Then, the attendant needs only to loosen thehandle 14 from drainage outlet 52 to easily withdraw the rod 12 ofstiffener and former 10. The catheter 30 is then in operationalplacement and the stiffener and former may be discarded.

In practice it is envisioned that such catheters could be supplied tothe physician or hospital with the stiffener and former 10 alreadyinserted therein. After one use only, the stiffener and former wouldthen be discarded. Such capability has the obvious advantages ofsterilization assurance, and the minimal cost of stiffener and formers10 should be quite acceptable for the disposability concept.

Some properties which make a catheter and former combination mostdesirable are (1 a certain degree of stiffness for ease of insertion;(2) some angulation at the tip to allow the tip to ride overobstructions; (3) highest proportion of luminal to catheter diameterratio; (4) flexibility and softness of the catheter once inserted so asto not to cause undue stress and pressure on the fragile surface of theurethra; (5) inertness of the catheters material; (6) reduced expense;and (7) the facility of use. Previously used wire guides did not havethe optimum compromise of qualities and were quite difficult to usesafely and handily since the wireguided catheter could not be reliedupon to ride over obstructions but rather to constantly endangerpiercing of the urethral wall.

With the present shortage of qualified doctors, more and morecatheterizations are done by nurses and physicians assistants, andgenerally speaking they do not have sufficient training orqualifications to perform difficult catheterizations which require theuse of a stylet or, more important, they do not recognize thecomplications which may result from the use of the conventionalstyle'ts. Thus, the present invention converts the usual Foley catheterinto an instrument capable of performing many of the more difficult aswell as the row tine catheterizations safely.

In summary, the aims and design of the catheter stiffener and-formerpermit the use of a soft pliable urethral catheter. with a largedrainage lumen as compared to the catheter diameter. The catheter wallscan be made thinner to increase the ratio of lumen to catheter size,thus allowing more free drainage of urine from the bladder duringoperative usage. The stiffener and former will permit easy passage ofthe catheter through the normal urethral canal or when narrowed,angulated, or otherwise obstructed through disease, such passage beingmade safely without buckling or collapsing of the drainage channels. Thecatheter stiffener is designed to be cheap and amenable to massproduction as it can be packaged already within the catheter and readyfor the insertion procedure.

Changes may be made in the combination, arrangement and size asheretofore set forth in the specification and shown in the drawings; itbeing understood that changes may be made in the embodiments disclosedwithout departing from' the spirit and scope of the invention as definedin the following claims.

What is claimed is:

1. An improvement for use in combination with urethral catheters of thetype having a drainage lumen and a reduced diameter inflation lumendisposed in parallel through the length thereof, a proximal end forinsertion in the urinary bladder, and a distal end including an enlargeddiameter drainage outlet communicating with the drainage lumen and aninflation control outlet communicating with said inflation lumen, theimprovement consisting of a stiffener and former device comprising:

rod means of uniform cross-sectional configuration and reduced lengthrelative to said drainage lumen and extending from proximal to distalends and having a diameter which is substantially less than that of saiddrainage lumen for insertion therein throughout the length thereof, saidproximal end being formed with an optimal curvature;

a handle portion secured to the distal end of said rod means, saidhandle portion being formed with uni- 6 form cross-section slightlylarger than said drainage said plastic material is nylon. outlet; 5. Theimprovement as set forth in claim 3 which is whereby said rod means maybe inserted throughout further characterized in that:

the entire length of said drainage lumen with said said rod means andsaid handle means are unitarily handle means tightly received within thedrainage 5 formed as uniform, round elements having preoutlet of saidurethral catheter to stiffen the cathedetermined respective diameters.ter while reducing its overall circumference for 6. The improvement asset forth in claim 5 which is urethral insertion. further characterizedin that: 2. The improvement as set forth in claim 1 which is said rodmeans has a diameter of approximately Ill 6 further characterized inthat: 10 inch and said handle means has a diameter of apsaid rod meansproximal end curvature is formed as proximately three-eights inch. 7

two substantially equal angular bends subtending 7. The improvement asset forth in claim 6 which is an arc defining said optimal curvature.further characterized in that: 3. The improvement as set forth in claim1 which is said rod means and said handle means are unitarily furthercharacterized in that: formed from nylon.

said rod means and said handle means are formed 8. The improvement asset forth in claim 1 wherein: I from resilient plastic material saidurethral catheter is the type known as the Foley 4. The improvement asset forth in claim 3 which is urethral catheter. further characterizedin that:

1. An improvement for use in combination with urethral catheters of thetype having a drainage lumen and a reduced diameter inflation lumendisposed in parallel through the length thereof, a proximal end forinsertion in the urinary bladder, and a distal end including an enlargeddiameter drainage outlet communicating with the drainage lumen and aninflation control outlet communicating with said inflation lumen, theimprovement consisting of a stiffener and former device comprising: rodmeans of uniform cross-sectional configuration and reduced lengthrelative to said drainage lumen and extending from proximal to distalends and having a diameter which is substantially less than that of saiddrainage lumen for insertion therein throughout the length thereof, saidproximal end being formed with an optimal curvature; a handle portionsecured to the distal end of said rod means, said handle portion beingformed with uniform cross-section slightly larger than said drainageoutlet; whereby said rod means may be inserted throughout the entirelength of said drainage lumen with said handle means tightly receivedwithin the drainage outlet of said urethral catheter to stiffen thecatheter while reducing its overall circumference for urethralinsertion.
 2. The improvement as set forth in claim 1 which is furthercharacterized in that: said rod means proximal end curvature is formedas two substantially equal angular bends subtending an arc defining saidoptimal curvature.
 3. The improvement as set forth in claim 1 which isfurther characterized in that: said rod means and said handle means areformed from resilient plastic material.
 4. The improvement as set forthin claim 3 which is further characterized in that: said plastic materialis nylon.
 5. The improvement as set forth in claim 3 which is furthercharacterized in that: said rod means and said handle means areunitarily formed as uniform, round elements having pre-determinedrespective diameters.
 6. The improvement as set forth in claim 5 whichis further characterized in that: said rod means has a diameter ofapproximately 1/16 inch and said handle means has a diameter ofapproximately three-eights inch.
 7. The improvement as set forth inclaim 6 which is further characterized in that: said rod means and saidhandle means are unitarily formed from nylon.
 8. The improvement as setforth in claim 1 wherein: said urethral catheter is the type known asthe Foley urethral catheter.